Carpet tile offers a number of economic advantages and conveniences over traditional "broad loom" carpeting. This is particularly true with regard to ease of repair or replacement of specific areas which are subject, for whatever reason, to heavy or uneven traffic patterns.
Carpet tiles, however, also have some recognized disadvantages in the form of substantial production and quality control problems. These are reflected in relatively high unit cost plus substantial variation in quality and durability.
For example, a relatively heavy extrusion backing and adhesive layer(s) arranged between the backing and primary carpet tile facing must supply most of the flexibility, weight and structural strength of conventional carpet tile. Not many conventional tile backing components, however, are capable of satisfying all of these needs. Furthermore, production and environment demands place a severe limitation on one's choice of possible facing/backing tile combinations, particularly with respect to environmentally-acceptable adhesives which can be successfully used to bind carpet facing and backing layers under high speed production conditions.
Moreover, high-speed commercial production usually requires a prestretching of primary facing and various backing layers to smooth out wrinkles and obtain an even surface for application of adhesive and eventual mating and cooling to form the uncut tile.
This, in turn, results in a number of problems since (a) very few, if any, primary carpet facings enjoy the same elastic properties as the tile base or the usual intermediate tile layers, and (b) few adhesive compositions, particularly environmentally acceptable adhesives, can be set up precisely enough to avoid or minimize inherent stress between the respective tile components and avoid damage to unset adhesive layers or warpage of the tile product. As a result, replacement or expensive post-lay down tile annealing treatment may become necessary.
As above noted, heavy extruded PVC tile bases of the usual type can provide adequate tile strength and weight, but at the expense of flexibility, to compensate for surface irregularities of a floor or corresponding surface. Such deficiency usually results in cracking and excess slippage of the applied tile.
It is an object of the present invention to develop a class of carpet tiles having widely varied primary facing/ backing combinations, which can be efficiently fabricated using conventional roll coating techniques under production conditions.
It is a further object to increase flexibility and durability of carpet tile.
It is a still further object of the present invention to promote efficient use of environmentally acceptable hot melt adhesives and sizing compositions for fabricating and various carpet tile facing and backing combinations under high speed production conditions.